Apparatus for guiding, conveying or treating a fiber cable

ABSTRACT

An apparatus for guiding, conveying or treating a fiber cable  7 , comprising several driven rollers  2, 3, 4.1, 4.2 , the fiber cable being guided along the circumference of the rollers so as to partly wrap therearound. The rollers include a roller  2  for feeding the fiber cable and a roller  3  for discharging the fiber cable. The remaining rollers  4.1, 4.2, 4.3, 4.4  are disposed relative to the feeding roller and the discharging roller in such a way that the fiber cable can be guided on the rollers at a respective angle of contact of &gt;180°. In order to involve all rollers to the same extent, the feeding roller and the inlet of the fiber cable, as well as the discharging roller and the outlet of the fiber cable, are arranged relative to each other such that the fiber cable can be guided along the circumference of the feeding roller and along the circumference of the discharging roller so as to partly wrap therearound at a respective angle of contact of &gt;180°.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of international applicationPCT/EP2004/010117, filed 10 Sep., 2004, and which designates the U.S.The disclosure of the referenced application is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention relates to a apparatus for guiding, conveying or treatinga fiber cable of the type which includes a plurality of driven rollers.

In the production of synthetic fibers, it is known that the individualspun fiber bundles are merged together into a fiber cable and are drawnfrom the spinneret using a apparatus comprising several driven rollers.Sufficient fiber tractive force must be generated by the rollers inorder to draw all the fiber strands forming the fiber cable evenly fromthe spinneret. In order for a defined spinning denier to be set whenguiding the fiber cable, there must be no occurrence of any slip betweenthe fiber cable and the rollers, especially in the outlet region. Allthe rollers can thereby be driven at an equal circumferential speed orat a differential speed for the purpose of imparting a draw.

For the build-up of the tractive forces as well as for preventing anyslip, the fiber cable must be guided on the rollers at certain minimumangles of contact. The sum of all the angles of contact on the rollersfunctions as the measure for the maximum producible tractive force. Six,eight or even more rollers are thus used for drawing the fiber cables.Such a apparatus is known, for example, from DE 24 55 117 A1. This knownapparatus has a feeding roller for feeding the fiber cable and adischarging roller for discharging the fiber cable. Between the feedingroller and the discharging roller, altogether five additional rollersare arranged offset relative to one another in such a way that the fibercable can be guided on the rollers arranged in-between at the largestangles of contact possible.

The problem occurring in case of such a plurality of rollers, however,is that the physical coherences (Eytelwein's rope friction formula) leadto a variable load of the rollers. Additional fluctuations in thecoefficients of friction between the individual pairings of the fibercable and the rollers due to, for example, inequalities in thepreparation and/or in the preparation order of the fiber cable,reinforce such inequalities.

It is therefore an object of the invention to further improve aapparatus of the abovementioned type for guiding, conveying or treatinga fiber cable in such a way that the previously mentioned disadvantagesdo not occur.

Another object of the invention is to create a generic apparatus whereinthe largest possible tractive forces can be generated using relativelyfew rollers for guiding the fiber cable.

SUMMARY OF THE INVENTION

The above and other objects and advantages of the invention are achievedby arranging the feeding roller and the inlet of the fiber cable, aswell as the discharging roller and the outlet of the fiber cable,relative to one another in such a way that the fiber cable can be guidedalong the circumferences of the feeding roller and the dischargingroller so as to partly wrap therearound at an angle of contact of >180°.

Preferred embodiments of the invention are defined by the features andthe combinations of features as further described below.

The invention is based on the recognition that according to Eytelwein'scorrelation, the rollers, especially in the outlet region are lightlyloaded if the requirement of uniform circumferential speeds is met. Theapparatus according to the invention prevents this by guiding the fibercable even on the discharging roller so as to wrap therearound to themaximum extent possible. A required total wrap is thus achieved usingfewer rollers and secondly due to the larger angle of contact, thedischarging roller can be used and loaded for building up the tractiveforces.

The invention further provides for the feeding roller and the inlet ofthe fiber cable to be arranged so as to achieve a large angle of contactof >180°. Each of the rollers can thus be used to a high utilizationdegree so that it is possible to generate relatively large total wrapsusing few rollers and thus relatively large tractive forces for drawingor stretching the fiber cable.

This effect can be further improved in that the fiber cable can beguided on all the rollers so as to partly wrap therearound at arespective angle of contact of >190°, preferably of >200°.

In doing so the rollers can be arranged in such a way that the fibercable is guided on each of the rollers at a substantially equal angle ofcontact.

However, it is also possible to configure the angles of contact on thefeeding roller and the discharging roller variably in proportion to theangles of contact on the remaining rollers.

In an advantageous arrangement of altogether four rollers, theadditional rollers can be arranged between the feeding roller and thedischarging roller so that the fiber cable can be guided with eventransitions between the rollers.

However, it is also possible to arrange the feeding roller and thedischarging roller between the additional rollers. The result is alonger free guiding passage for the fiber cable between the additionaloutboard rollers. Using a corresponding selection of the angles ofcontact, total wraps of >900° can be achieved even when using fourrollers.

In order to be able to create larger total wraps of >1,000° and alsolarger draw forces or stretch forces, three or more than three rollerscan advantageously be arranged between the feeding roller and thedischarging roller.

In cases in which differential speeds between the individual rollers arerequired, the drive motors of the rollers are controlled advantageouslyusing individual converters in each case. In case the circumferentialspeed of the rollers is equal, each of the drive motors can becontrolled using a common group converter. A mechanical coupling of therollers in connection with a drive motor is also possible.

The apparatus according to the invention is thus suitable especially fordrawing and stretching fiber cables using the least possible number ofrollers. Simple handling is thus achieved, in that there are fewer fibertransfers between the individual rollers. Economizing on everyadditional fiber transfer simultaneously involves a reduction in therisk of roll formation. The apparatus according to the invention thusrepresents a cost effective technical solution for guiding, conveyingand treating a fiber cable.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the apparatus according to the invention aredescribed in more detail in the following description, with reference tothe enclosed drawings, of which:

FIG. 1 schematically illustrates the top view of a first embodiment ofthe apparatus according to the invention;

FIG. 2 illustrates a side view of the first embodiment;

FIG. 3 schematically illustrates a second embodiment of the apparatusaccording to the invention, said embodiment comprising four rollers;

FIG. 4 schematically illustrates a third embodiment comprising fourrollers;

FIG. 5 schematically illustrates a fourth embodiment comprising fourrollers;

FIG. 6 schematically illustrates another embodiment of the apparatusaccording to the invention, said embodiment comprising five rollers;

FIG. 7 schematically illustrates an embodiment of the apparatusaccording to the invention, said embodiment comprising six rollers; and

FIG. 8 schematically illustrates another embodiment comprising sixrollers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 2 schematically illustrate a first embodiment of theapparatus according to the invention. FIG. 1 illustrates a top view ofthe embodiment without the guiding of a fiber cable and FIG. 2illustrates the side-view of the embodiment with the guiding of a fibercable. The following description applies to both the figures unlessexplicit reference is made to either of the figures.

A feeding roller 2, a discharging roller 3 and additional rollers 4.1and 4.2 are arranged next to one another on a support wall 1. Therollers 2, 3, 4.1 and 4.2 are designed identically and are heldrotatably with one drive end on the support wall 1. The drive ends ofrollers 2, 3, 4.1 and 4.2 are each coupled to a drive motor 8. Aconverter 9 is assigned to each of the drive motors 8, each of whichdrive motors 8 can be controlled using the converter.

The arrangement of the feeding roller 2, the discharging roller 3 andthe rollers 4.1 and 4.2 is selected in such a way that the each of theoutboard rollers 4.1 and 4.2 is held at a large distance from oneanother on the support wall 1. The rollers 4.1 and 4.2 are located in ahorizontal plane opposite to and at a distance from one another.

Between the rollers 4.1 and 4.2, the feeding roller 2 and thedischarging roller 3 are arranged at a short distance from one anotherin a second horizontal plane. The second horizontal plane is positionedbelow the first horizontal plane, in which the rollers 4.1 and 4.2 arearranged. The distance between the two horizontal planes is selected insuch a way that a fiber cable 7 fed horizontally using an inlet 5 can besupplied freely from outside to the feeding roller 2 without any contactwith the upstream roller 4.1. The fiber cable 7 can thus be guided awayaccordingly using an outlet 6 by the discharging roller 3 horizontallywithout any contact with the downstream roller 4.2. What is achieved bythe symmetrical arrangement of the rollers 2 and 3, and also 4.1 and 4.2is that each fiber cable 7 can be guided on the rollers 2, 3, 4.1 and4.2 at the same angle of contact α. The thus attainable angle of contactα could have a value of, for example, 227.5° so as to achieve a totalwrap of 910°. The fiber transition from the feeding roller 2 to theroller 4.1 and also the fiber transfer from the roller 4.2 to thedischarging roller 3 are configured identically for this purpose.

The embodiment illustrated in FIGS. 1 and 2 of the apparatus accordingto the invention could be used for guiding and conveying a fiber cable,all the rollers in said embodiment being driven at equal circumferentialspeed. In such a case, the drive motors 8 of the rollers 2, 3, 4.1 and4.2 are controlled collectively by a group converter 10, as illustratedin FIG. 1 by the dashed lines.

FIGS. 3, 4 and 5 schematically illustrate additional embodiments of theapparatus according to the invention, each of said embodimentscomprising four rollers. FIGS. 3, 4 and 5 each illustrate the side-viewof each of the different arrangements of the rollers, wherein theadditional rollers 4.1 and 4.2 are each arranged between the feedingroller 2 and the discharging roller 3. The design of the apparatus beingsubstantially identical to the preceding example, reference is made tothe description of FIGS. 1 and 2. Only the differences are explainedbelow in more detail.

In FIG. 3, the feeding roller 2 and the discharging roller 3 arearranged in a vertical plane on top of one another. The two additionalrollers 4.1 and 4.2 are arranged in a horizontal plane centrally betweenthe feeding roller 2 and the discharging roller 3. The distances betweenthe rollers are configured in such a way that a fiber cable 7 is guidedalong the circumference of the rollers 2, 4.1, 4.2 and 3 so as to partlywrap around each roller. The fiber cable 7 is guided on the feedingroller 2 and the discharging roller 3 at an angle of contact α. Incontrast, a slightly larger contact angle β is attained in case of theadditional rollers 4.1 and 4.2. The angle of contact α on the feedingroller 2 and on the discharging roller 3 is configured to be >200°. Forthis purpose the inlet 5 of the fiber cable 7 is embodied diagonallyabove the feeding roller 2. Accordingly, the outlet 6 of the fiber cable7 is embodied diagonally below the discharging roller 3.

FIG. 4 illustrates another possible arrangement of the four rollers.Here, the feeding roller 2 and the roller 4.2 are arranged in a firstvertical plane on top of one another with a distance in-between and theroller 4.1 and the discharging roller 3 are arranged in a secondvertical plane on top of one another with a distance in-between. Therollers 2, 4.1, 4.2 and 3 are arranged offset relative to one another inthe two vertical planes lying next to one another. The inlet 5 and theoutlet 6 of the fiber cable 7 are identical to the preceding embodimentillustrated in FIG. 3. Here too, the fiber cable 7 is guided on thefeeding roller 2 and on the discharging roller 3 at an angle of contactα. The fiber cable 7 is guided on the additional rollers 4.1 and 4.2 atan angle of contact β. The angle of contact β is marginally larger thanthe angle of contact α. An angle of contact α of >200° can beadvantageously achieved due to the diagonal arrangement of the inlet 5and the outlet 6.

FIG. 5 illustrates an arrangement of the four rollers, wherein an angleof contact α200° is also attained on the feeding roller 2 and thedischarging roller 3. However, here the fiber cable 7 is fedhorizontally using the inlet 5 and is discharged horizontally using theoutlet 6. The rollers 2, 4.1, 4.2 and 3 are held in an offsetarrangement on top of one another. A larger angle of contact β isattained on each of the additional rollers 4.1 and 4.2.

The arrangements of the rollers illustrated in the FIGS. 3 to 5 enablethe attainment of individual angles of contact of up to a maximum of230°. An increase and/or the order of magnitude of the angles of contactis substantially limited by the predetermined minimum distances betweenthe rollers, said distances being necessary for applying a fiber cable.In case of a roller diameter of, for example 800 mm, the minimumdistances between the rollers of approximately 150 mm are required forapplying the fiber cables.

FIG. 6 schematically illustrates the side view of another embodiment ofthe apparatus according to the invention. Here also, a top view isomitted since the design is substantially identical to the embodimentillustrated in FIGS. 1 and 2. In this respect, reference is made to thedescription of FIGS. 1 and 2 and only the differences are explainedbelow.

In the embodiment according to FIG. 6, altogether three additionalrollers 4.1, 4.2 and 4.3 are arranged between a feeding roller 2 and adischarging roller 3. The arrangement is thereby selected in such a waythat the feeding roller 2, the roller 4.2 and the discharging roller 3are arranged in a first vertical plane and at a distance from oneanother. The rollers 4.1 and 4.3 are arranged in a second adjoiningvertical plane. A minimum distance between the rollers is maintained asa result of which the roller 4.1 is arranged centrally relative to thefeeding roller 2 and the roller 4.2 arranged thereabove. Accordingly,the roller 4.3 is held centrally next to the roller 4.2 and thedischarging roller 3. The inlet 5 is embodied diagonally above thefeeding roller 2. The outlet 6 is embodied diagonally below thedischarging roller 3, so that the fiber cable 7 is guided on the feedingroller 2 and the discharging roller 3 at an angle of contact of >180°.The distance between the feeding roller 2 and the roller 4.2 arrangeddirectly thereabove in the vertical plane is configured to be smallerthan the roller diameter of the roller 4.1 so that large angles ofcontact of >200° are possible when guiding the fiber cable 7 from thefeeding roller 2 to the additional rollers 4.1 and 4.2. Thus the totalangle of contact of >1,000° can be attained using the embodimentillustrated in FIG. 6. The transition between the individual rollers isconfigured to be substantially equal.

For building up still greater draw forces or stretch forces even sixrollers can advantageously be integrated into a apparatus according tothe invention. The possible examples for the arrangement of the rollersare illustrated in the FIGS. 7 and 8. Here a horizontal inlet and outletof the fiber cable are implemented for each of the feeding rollers 2 andthe discharging rollers 3. In all other respects, reference is made tothe design of the apparatus illustrated in FIGS. 1 and 2.

In the embodiment according to FIG. 7, four additional rollers 4.1, 4.2,4.3 and 4.4 are each arranged offset relative to one another between thefeeding roller 2 and the discharging roller 3. Here the roller distancesbetween the individual rollers are configured to be equal so that theindividual angles of contact result in guiding a fiber cable with atotal wrap of >1,200°.

In the embodiment illustrated in FIG. 8, the six rollers are arranged intwo groups, wherein the first group is formed by the feeding roller 2and the two rollers 4.1 and 4.2 arranged downstream and offset relativeto one another. The second group of the rollers comprises thedischarging roller 3 and the rollers 4.3 and 4.4 arranged offsetrelative thereto. Here also, the fiber cable is guided on the individualrollers at angles of contact measuring between 180° and 230°.

The embodiments illustrated in the FIGS. 1 to 8 of the apparatusaccording to the invention can be used for drawing one or more fibercables in a spinneret. The inlet 5 could be formed, for example, by adeflecting roller, which is arranged directly downstream of a spinneretand which merges together the individual freshly spun fiber bundles intoa fiber cable. The outlet 6 could be formed, for example by a guideroller arranged directly upstream of a winder.

Furthermore, all the embodiments illustrated in the FIGS. 1 to 8 of theapparatus according to the invention can be used for drawing one or morefiber cables or for thermally treating one or more fiber cables. Therollers can comprise additional heating or cooling agents for thispurpose.

Multiple apparatuses according to the invention are used in parallel fordrawing one or more fiber cables, wherein said apparatuses, due to thedifferent speeds, bring about a drawing of the fiber cables between theindividual apparatuses.

Many modifications and other embodiments of the invention set forthherein will come to mind to one skilled in the art to which theinvention pertains having the benefit of the teachings presented in theforegoing description and the associated drawings. Therefore, it is tobe understood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

1. An apparatus for guiding, conveying, or treating a fiber cablecomprising a plurality of driven rollers positioned so that a fibercable can be guided along the circumference of each roller so as topartially wrap therearound, said driven rollers including a feedingroller positioned adjacent an inlet for the fiber cable, a dischargingroller positioned adjacent an outlet for the fiber cable, and aplurality of additional rollers arranged relative to the feeding rollerand the discharging roller so that the fiber cable can be guided on therollers at a respective angle of contact which is >180°, and wherein thefeeding roller and the inlet for the fiber cable and the dischargingroller and the outlet for the fiber cable are arranged relative to eachother such that the fiber cable can be guided along the circumference ofthe feeding roller and the circumference of the discharging roller so asto partially wrap therearound at a respective angle of contact whichis >180°.
 2. The apparatus according to claim 1, wherein the fiber cableis guided on all the driven rollers so as to partly wrap therearound ata respective angle of contact of >190°.
 3. The apparatus according toclaim 1, wherein the angle of contact on all the rollers are ofsubstantially equal measure.
 4. The apparatus according to claim 1,wherein the angle of contact on the feeding roller and the dischargingroller and/or the angle of contact on the additional rollers are ofsubstantially equal measure.
 5. The apparatus according to claim 1,wherein altogether two additional rollers are provided.
 6. The apparatusaccording to claim 5, wherein the additional rollers are arrangedbetween the feeding roller and the discharging roller.
 7. The apparatusaccording to claim 5, wherein the feeding roller and the dischargingroller are arranged between the additional rollers.
 8. The apparatusaccording claim 1, wherein altogether three additional rollers arearranged between the feeding roller and the discharging roller.
 9. Theapparatus according to claim 1, wherein altogether more than threeadditional rollers are arranged between the feeding roller and thedischarging roller.
 10. The apparatus according to claim 1, wherein adrive motor is assigned to each of the driven rollers, and wherein thedrive motors are controlled by several individual converters or by agroup converter.
 11. The apparatus according claim 1, wherein therollers are mechanically coupled by toothed wheels or chains and aredriven by a drive motor using a converter.